You said;
"Today, at this space and time, all the life we know, or have ever known, found its origins here, on this lonely, fertile growing-field called Earth."

There are theories that claim ‘space’ or other planets as the origination of life on Earth.

"We shall have to wait for what the future may tell."

True, but would you be surprised if it turns out that ‘life’ is very common in the universe?

"The numbers you seek, regarding lost quantities of atmospheric particles, are not with me. I find the sum of “miniscule” to be sufficient data. The Solar wind pounds at a regular speed of between 200 km/s and 900 km/s, but with a density of very near zero (1 to 10 protons per cubic centimeter). Our astronauts bounced through it with relative ease on the Moon, and the posted flags never rippled."

I agree with you on the subject matter of solar wind and its density. But without numbers on the amount of radiation being added to the upper atmosphere by nuclear ‘leaks’ from reactors all over the world, it is difficult to know if the ‘polar fountain’ has increased in magnitude since the invention of nuclear power.

"As for the environment of Mars, there is no magnetosphere to protect what little atmosphere she holds, and there is no shield against the Solar wind, meteor storms, or coronal mass ejections. It’s a radio-hot planet, one we will need to be very prepared for when we eventually go."

At least there is 'water' or ice on the planet, should make it easier to quench our thirst. ;-)

"About moisture, here’s a new one, just in from Goddard:"

Thank you; very interesting.